The subject matter disclosed herein relates to a massage device for a vehicle seat.
Massage devices for a backrest of a vehicle seat have been proposed, such as for example, in U.S. Pat. No. 5,135,282. A linear series or sequence of inflatable massage cells is arranged in the vicinity of the inner surface of the cover of the backrest of the vehicle seat. More than one linear series of massage cells may also be arranged in parallel and adjacent to one another in the backrest, said massage cells then being simultaneously operated in order to carry out a sequential inflation and venting of the massage cells along the linear sequence of massage cells. Such a sequential inflation and venting of the massage cells along the linear series causes a deformation which propagates in a wave-like manner along surface of the backrest, which propagating deformation is accompanied by a force acting on the back of the driver, which force is directed transverse to the surface of the backrest. Such a pushing force which propagates along the linear series of massage cells is particularly desired for a good massage effect. The massage device has a supply line structure including supply and venting lines, in particular a supply line is provided which connects the successive massage cells in series. Moreover, a venting line is provided which accordingly connects the sequence of successive massage cells in series. The venting line may be opened relative to the surrounding atmosphere in order to vent the massage cells. In order to produce inflation along the linear series of massage cells propagating in a wave-like manner, and accordingly to cause venting progressing in a wave-like manner along the linear series of massage cells, or in order to cause the expansion of individual massage cells, a valve arrangement with a plurality of controllable valves and a control unit for said valves is present. In particular, a controllable valve is present at the start of the supply line upstream of the first massage cell, and a controllable valve is present between each pair of successive adjacent massage cells. The venting line is likewise provided with controllable valves. In order to start an inflation cycle, initially the valve upstream of the first cell in the linear series is opened and as a result the first massage cell is supplied with compressed air from the compressed air pump via the supply line. After inflation of the first massage cell, the control unit opens the valve to the second massage cell etc., until all massage cells are inflated. Subsequently, a sequential venting of the massage cells begins in reverse sequence. In the massage device disclosed in U.S. Pat. No. 5,135,282 the massage cells are spaced apart from each other along the linear series of massage cells, i.e. between each pair of adjacent massage cells a gap remains.
Moreover, further structures of supply line and valve arrangements are known, such structures permitting that each massage cell in the linear sequence of massage cells is selectively inflated or vented individually and independently of all of the other massage cells, i.e. the sequence of massage cells is not connected “in series”, but a supply line controlled by a controllable valve is provided for each massage cell individually. Such a structure of supply and venting lines with associated valves permits to cause a deformation propagating in a wave-like manner, by inflation propagating along the linear series of massage cells, wherein the wavelength of the deformation propagating in a wave-like manner may be substantially smaller than the longitudinal extension of the linear series, i.e. in each case only one or very few neighboring massage cells are inflated to a maximum extent, whilst the next neighboring massage cell is already in the state of starting inflation and the preceding massage cell is already being vented.
Massage devices of the type as described above which, due to the deformation in the seat surface propagating in a wave-like manner, achieve a good massage effect, are of rather complicated design since a large number of valves is needed for control, in the worst case two valves per massage cell for controlling supply and venting of the massage cell. This implies rather high costs for the valves themselves on the one hand, and requires on the other hand a rather complicated assembly process involving the provision of a connection between each of the valves and the control unit.
Accordingly, while existing vehicle seats are suitable for their intended purpose the need for improvement remains, particularly in providing a vehicle seat with massage functions that is less expensive and simpler to assemble.